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Show 420 HABITS OF INSECrrs CIIAl:'. XI. we shall presently see that this hol<ls good in their felonious practice of biting holes through_ the corolla. It ·. curious question how bees recognise tho flowers of th~s :a1ne species. That the coloured corolla is the chief gnide cannot be doub_t~<l.' On a_ fine day, when hive-bees were incessantly v1s1ttng the httle blue flowers of Lobelia erinus, I cut off all the petals of so1no, and only the lower striped petals of others, and these flowers were not once again sucked by the bees, although smne actually crawled over the1n. 'rhe re~oval of ~he tw_o little upper petals alone made no difference In theu visits. Mr. J. A.nderson likewise states that when~~ re- 1noved the corollas of the Calceolaria, bees never VISited the flowers.* On the other hand, in soine large masses of Gm"aniurn phmun~. which had escaped out of a _gai~uen, I observed the unusual fact of the flowers cont1nu1ng to secrete an abundance of nectar after all the petals had fallen off; and the flowers in this state were still visited Ly huinble-bees. But the bees might have le~rnt that these flowers with all their petals lost were still worth visitina by finding nectar in those with only one or two lobst'. ~ The colour alone of the coro lla serves as an approxi1nate guide: thus I watched_ for some time huinble-bees which were visiting exclusively plants of * ~Gardeners' Chronicle,' 1853, p. 534. Kurr cut off the nectaries from a brge number of flower.:~ of several species, and found that the greater number yielded seeds ; but inseuts probably would not perceive the lo~s of the n~ctary until they had msmtcd thmr prob oscides into the holes thus formc<l, and in doing. so would. fertilise the flowers He ah;o removed the whole corolla from a (' !) Jlsidcru.ble number of flowers, and thl'.se likewi8c yield 'd seed,. .Flower::; which are ~:;elf- fertile woulu nu.turally produce seeds under these circum ·tances ; but .r am greatly surprbecl tl1at Delph'tniUin consolida, as well as another species of Delphinium, a~ld Viola tricolor should h,we P10- duced a fair s~pply of seedi:l when tlms treated· but it docs not Appear that h e ~omparod tho nunl~er of the seed:; thus procluc~ ·d. with those yicldeu by unmutllrlted. flower.-; left to tile free access ~f in::;ects: I Bedeutung dor N ~;ktarien,' 1833, PP· 12;)-1:35. CHAP. XI. IN RELATION TO CROSS-FERTILISATION. 4~1 the white-flowered Spiranthes autumnalis · h f . , growing on s ort tur at a considerable distance apar·t. 1 tl • • • c , anc 1 se bees oft~n fie': Within a few inches of several other pla~ts :v1th white flowers, and then without further xamn~ ation pass~d onwards in search of the Spiranthes. Again, m~ny hive-bees which confined their visits to the common hng (Call una vulgaris), repeatedly flew towards lJ!rica tetral~w, evidently attracted by the nearly similar tint of theu flowers, and then instantly passed on in search of the Call una. · That the colour of the flower is not the sole guide, is cle~rly shown by the six cases above given of bees which repeatedly passed in a direct line from one variety to ~nother of the sa1ne species, although they bore very differently coloured flowers. I observed also bees flying in a straight line fro1n one clump of a yellowflowered CEnothera to every other clump of the same plant in the garden, without turning an inch from their course to plants of Eschscholtzia and others with yellow flowers which lay only a foot or two on either side. In these cases the bees knew the position of each plant.in the garden rer~ectly well, as we may infer by the due~tness of theu flight; so that they were guided by expenence and memory. But how did they discover at first that the above varieties with differently coloured flowers belonged to the same species? Improbable as it. may appear, they seem, at least sometimes, to recognise plants even from a distance by their general aspect, in the same manner as we should do. On three occasions I observed humble-bees flying in a perfectly strai?ht line from a tall larkspur (Delphinium) which was In full flower to another plant of the same species a~ the distance of fifteen yards which had not as yet a s1ngle flower open, and on which the buds showed only a faint tinge of blue. Here neither odour nor the |